The present invention is in the field of Telephony communications and has particular application to methods including software for transforming the media type of a telephony call while it is still in progress as a means of assuring adequate bandwidth for the call.
Telephone call processing and switching systems are, at the time of the present patent application, relatively sophisticated, computerized systems, and development and introduction of new systems continues. Much information on the nature of such hardware and software is available in a number of publications accessible to the present inventor and to those with skill in the art in general. For this reason, much minute detail of known systems is not reproduced here, as to do so would obscure the facts of the invention.
One document which provides considerable information on intelligent networks is xe2x80x9cITU-T Recommendation Q.1219, Intelligent Network User""s Guide for Capability Set 1xe2x80x9d, dated April, 1994.
At the time of filing the present patent application there continues to be remarkable growth in telephone-based information systems (intelligent networks) including Internet based systems. Recently emerging examples are telemarketing operations and technical support operations, among many others, which have grown apace with development and marketing of, for example, sophisticated computer equipment. More traditional are systems for serving customers of such as large insurance organizations. In some cases, organizations develop and maintain their own telephony operations with purchased or leased equipment, and in many other cases, companies are outsourcing such operations to firms that specialize in such services.
A large technical support operation may serves as an example of some of the kinds of applications of telephone equipment and functions to which the present invention pertains and applies. Consider such a system having a country-wide matrix of call-in centers, which is more and more a relatively common practice to provide redundancy and decentralization, which are often considered desirable in such operations. Also in such large organizations, business firms have a national, and in many cases a world-wide customer base. Such a system handles a large volume of calls from people seeking technical information on, for example, installation of certain computer-oriented equipment. These calls are handled by a finite number of trained operators distributed over the decentralized matrix of call centers.
In an intelligent network such as described above, incoming calls placed from anywhere in the Public Switch Telephone Network (PSTN) arrive at central telephony switches called Service Control Points (SCP). An SCP is generally provided to be relatively close to a defined local area of callers. If the intelligent network is very large comprising many call centers then more than one SCP may be provided. Routing of incoming calls begins at the SCP.
A central router at the SCP routes incoming calls to other routers or telephony switches that are deployed throughout the network to provide further routing to call centers or customer information systems (CIS). Additional processors may be provided at the SCP for further computer enhancement. For example, when a call arrives at the SCP, information about the caller is collected and processed to help determine the final destination of the call. Then according to programmed routing rules, the call may be routed to an automatic call distributor (ACD) for further routing to a call center and then on to an available agent. In some networks (known to the inventor) digital information pertaining to the caller may arrive at an agent station before the analog call. Routing in an intelligent network may be accomplished on several levels according to many different protocols. It is the processor connected to the telephony switch that provides computer enhancement in an intelligent network.
More recently, there has been an integration between intelligent call processing systems and the public wide area network known as the Internet. A call center that is connected to both a public or private telephony network and the Internet can receive calls from either source. In an environment such as this, multimedia forms of communication may also be received such as E-mail, Internet phone calls, video calls and so on. An agent operating at a station equipped with an Internet connected PC as well as a public switch connected telephone can communicate using a wide variety of tools.
Internet-based telephony systems may utilize both a regular telephony network and the Internet backbone, as briefly described above, or be based exclusively on the Internet. The present invention pertains most particularly to those systems which rely on both intelligent telephony networks and the Internet, and may handle calls over either network. Therefore, in addition to CTI equipment normally applied to, for example, a publicly switched Telephony network, there are Internet connected processors adapted for the routing and processing of calls according to Internet Protocol (IP), as is known in the art.
The added capability of routing telephone calls over digital networks such as the Internet, and the additional communication options available to an Internet-connected call center can enhance a company""s ability to reach a large market as well as to service customers efficiently. Because of the shared nature inherent to portions of Internet infrastructure and Telephony infrastructure, the line separating the two mediums is often somewhat ill-defined. For example, traffic from Internet activity may share certain sections of infrastructure that are used for public telephony traffic, and so on.
One of the challenges faced with adapting real-time communication to being carried over a wide area network (WAN) such as the Internet, concerns available bandwidth. For example, a conventional (non-Internet) call to a call center arrives on dedicated lines that guarantee the bandwidth needed for the call. Any congestion issues regarding traffic in the network are typically handled with intelligent routing solutions. Connected digital networks such as local area network (LAN) or (WAN) share available bandwidth and are mostly utilized, in current art, for transferring information associated with a call, requesting routing of a call, controlling telephony switches, and so on. This state, as previously described, is not due to a lack of capability of transferring a real-time transaction over a digital network, but rather, to the uncertainty of available bandwidth during periods of high congestion in the network. For example, if a real-time transaction such as a telephone call is experiencing a drop in available bandwidth below a certain level, the call can break up or be delayed beyond a reasonable time rendering the transaction obsolete. Furthermore, real-time transactions being transported across a WAN such as the Internet require more bandwidth than other types of transactions that share the network. Because bandwidth is shared over a WAN, various uses must compete for available bandwidth. Portions of the Internet experience heavy congestion during certain times of the day, for example, raising the risk of the loss of real-time transactions to an Internet-connected call center.
Adaptive encoding techniques have been proposed to enable better real-time service during periods of high congestion on the Internet. These encoding techniques attempt to adapt transactions to lower Bandwidth thresholds that may occur along the path or route used during the transaction. Other techniques such as resource reservation protocol (RSVP) and real-time transport protocol (RTP) are used to secure bandwidth for a transaction and to insure that proper flow and identification of information is received. Both techniques use existing IP protocol. These techniques can be used in conjunction with, or independently from each other. However, these adaptations are not complete solutions to the problem of transporting real-time communication over a WAN.
What is clearly needed is a method and apparatus including software that enables a system to switch a real-time transaction between different protocols and paths, such as between Internet and ISDN, for example, based on detection and monitoring of available bandwidth as a call progresses. A method such as this could enable real-time transactions to be salvaged and delivered in alternate media form in the event that substantive bandwidth is not available along a certain portion of a WAN or delays are too long with a conventional telephony connection.
In a preferred embodiment of the present invention, a method for assuring quality of service for Data Network Telephony (DNT), in particular the example of Internet Protocol Network Telephony (IPNT) calls is provided, comprising steps of (a) monitoring bandwidth on an existing IPNT call between two stations; (b) comparing available bandwidth to a prestored threshold value; and (c) in the event that available bandwidth is less than the prestored threshold value, establishing a conventional telephone call via a telephony channel between telephones available to the participants in the IPNT call, and terminating the IPNT call. Bandwidth may be monitored by determining latency between two points, and in this case the prestored threshold value is a latency time value.
In some embodiments the system continues to monitor bandwidth for the IPNT path, and restores the IPNT call and terminates the conventional telephony call in the event that available bandwidth again is equal to or exceeds the prestored threshold value.
In preferred embodiments a single user interface for calls is provided at the stations where calls are completed, and in one case the interface comprises a telephone connected by its speaker line to the input and output of a sound card installed in the computer. None of the discussed aspects is specific to IPNT, but can be applied to DNT in general.
In some embodiments, before a switch of call type or network is made, one or both participants in the call are notified, and in some cases participants are provided with an opportunity to ratify or veto a contemplated switch.
In alternative aspects of the invention, apparatus adapted for practicing the invention is provided, wherein software for accomplishing the invention may be operated on a variety of platforms, depending on system content and connection. In yet other aspects, call center architecture is provided wherein various embodiments of the invention may be practiced.